1. Field of the Invention
The invention relates to a network interface device and a method thereof, and particularly to a network interface device and a method which is capable of increasing data communication efficiency.
2. Description of the Prior Art
Traditional data transmission and receipt mechanism of network relies on single network port corresponding to single network controller, to transmit and receive data between a host and a network through a host interface, for example, a PCI Express interface.
PCI Express 1.1 is operated at a 2.5 GHz clock rate, and achieves a bandwidth of 250 MB per second in one direction. In other words, both upload and download bandwidths of a PCI Express lane are 250 MB/s. Multiple lanes can be combined in the PCI Express interface to provide a higher bandwidth. Therefore, the bandwidth of a ×8 PCI Express interface is 8 times the bandwidth of a single-lane PCI Express interface, which means the bandwidth is 2 GB/s in one direction. Taking a ×16 PCI Express interface applied in a common display card for another example, the uni-direction bandwidth is 4 GB/s.
However, in both transmission and receipt, data communication speed of a Gigabit Ethernet network interface card is lower than Gigabit/s due to network surroundings. But many Gigabit Ethernet network interface card (NIC) use ×8 PCI-E interface whose bandwidth achieves 2 GB/s. Obviously, still half or more than half of PCI-E bandwidth is not fully used by the network controller. For a present PCI Express 2.0 interface, the clock rate is increased to 5 GHz to double the interface bandwidth which means uni-direction bandwidth of a ×8 PCI Express 2.0 interface achieves 4 GB/s. Accordingly, much more bandwidth is wasted in network communication.